http-json-query-exporter

Query http endpoints, transform and export response to prometheus.

Features

• Call any http endpoint that returns valid JSON
• Transform response with https://docs.jsonata.org (http://try.jsonata.org/)
• Exports results as https://prometheus.io/ metrics

Run

Using nodejs

Install dependencies

npm install

Start server

CONFIG_FILE=example/config.yml npm start

Get metrics

1. Queries https://httpbin.org/json
2. Runs transformation
3. Returns prometheus metrics

curl localhost:8000/all/metrics
# HELP items_per_slide_count this is my metric
# TYPE items_per_slide_count counter
items_per_slide_count{title="Wake up to WonderWidgets!"} 0
items_per_slide_count{title="Overview"} 2

Using docker

docker run --rm -p 8000 coliquiode/http-json-query-exporter

Configuring tasks

The configuration contains a collection of tasks. Each task consists of 3 steps:

1. query
2. transformation
3. prometheusMetric

Short example:

tasks:
  # task
  - query:
      url: 'https://httpbin.org/json'
    transformation: |
      $.slideshow.slides.{"title": title, "value": $count(items)}
    prometheusMetric:
      name: 'items_per_slide_count'
      type: 'counter'
      description: 'this is my metric'
  # further task(s)
  # - ...

This produces metrics like:

# HELP items_per_slide_count this is my metric
# TYPE items_per_slide_count counter
items_per_slide_count{title="Wake up to WonderWidgets!"} 0
items_per_slide_count{title="Overview"} 2

Detailed process

1. query step

Define a http query here, the only mandatory argument is url and it must return valid JSON.

All valid axios.request({...}) parameters like method, body, etc. are accepted https://github.com/axios/axios#request-config.

2. transformation step

Define JSONata queries to transform the http query result into a array of objects for exporting metrics:

• The object value keys are used reserved and used as metric value
• All other object keys are used as metric labels

Test transformations in http://try.jsonata.org/.

3. prometheusMetric step

Specify metric name, description and type. All labels and the value must be produced by previous transformation step.

CI Environment

See https://travis-ci.com/coliquio/http-json-query-exporter

License

See LICENSE.

Disclaimer

This is a project for the community, from developers for developers. This is NOT an official coliquio product. I.e. Maintenance and support are provided by the individual developers but not officially by coliquio.